The present invention relates to an improved method and apparatus for controlling movement of product to be coated from the down-bed region to the up-bed region of a Wurster-type fluid bed coater. The well-known Wurster apparatus and process is used for coating particulate material (such as powders, granules, seeds, beads, pellets or tablets) in a batch fluidized bed dryer. The fluid bed is widely used for drying powders, creating granules via agglomeration, or coating powders, granules or tablets of pharmaceutical, food and chemical ingredients.